We’ve long recommended the Avast anti-virus program, because it’s free. But a major flaw was recently uncovered by a Google researcher in what they called “Project Zero,” which aims for zero threats. The flaw in Avast allows a hacker to access your files and stored passwords. Ironically, the flaw shows up when you use the Avast “SaveZone” feature.

Another free program we’ve long recommended, MalwareBytes, also received criticism from Project Zero. Updates for Malwarebytes programs are downloaded without encryption. That means an attacker could replace the updates with their own evil code. Though Malwarebytes says a fix is in the works, it’s a little disconcerting.

There are many other anti-virus alternatives, but nearly all have an annual subscription fee. We’ve used Bullguard Internet Security for the last five years and haven’t had any security problems, but it’s $50 a year. We’ve seen some great reviews for Kaspersky, another problem blocker, but haven’t tried it yet.